Machine for measuring two-fluted taps



April 19, 1932. H. M.-ALLISON ET-AL I MACHINE FOR MEASURING TWO-FLUTEDTAPS Original Filed Oct. 22, 1928 5 SheetsSheet WWW: -Wier VWY- 1 H a aW 6 6. 6 if ww" A ril 19, 1932. H. M. ALLISON ET AL 1,854,244

\ MACHINE FOR MEASURING TWO FLUTED TAPS Original Filed Oct. 22, 1928 3Sheets-Sheet 2 =-Qru1 F v a 122 am :3- 5 F 13.4% V 26 20 I 232:1: 65 J23I SSheets-Sheet 3 H. M. ALLISON ET AL Original Filed Oct. 22, 1928 I l I-1 MACHINE FOR MEASURING TWO-FLUTED TAPS qfiwfifw A 0 :1 J L i? 4 r 2 4M 6 w 3 b mm 2 Z 1 7 m i...

April 19, 1932.

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7 v I a 1/. im W; .M 2 T %W www 4i Patented Apr. 19, 1932 LIME HARVEY M.ALLISON AND ERNEST A. WALKER, F WORCESTER, MASSACHUSETTS, AS

SIGNORS TO J OHN BATH, OF WORCESTER, MASSACHUSETTS MACHINE FOR MEASURINGTWO-FLUTED TAPS Original application filed'october '22, 1926, Serial No.1930.v Serial This is a division of. our prior application Serial No.314,032, filed by us October 22, 1928.

This invention relates to a machine for 3 measuring taps or otherthreaded workand particularly to a machine for indicatmg variations insize of such work with respect to a standard or master gauge.

It is the general object of our inventlon to 10 provide a machine bywhich such measurements and comparisons may be quickly and easily madeand by which the comparative variations from a standard gauge willbeplainly shown. I

A further object is to provide a measuring machine which may be readilyadapted to the measurement of taps of diiferent sizes and pitches. 1

Our invention further relates to arrange- 20 ments and combinations ofparts which will be hereinafter described and more particularly pointedout in the appended claims.

' An operative form of the invention is shown in the drawings in whichFig. 1 is a plan view of our improved ma chine, adapted to themeasurement of twofluted taps;

Fig. 2 is a side elevation thereof, partly 'in section, and looking inthe direction of. 30 the arrow 2 in Fig. '1;

Fig. 3 is a partial sectional front elevation,

taken along the line in Fig. 1;

Fig. 4 is a sectional plan view. taken along the line 44 in Fig. 3; H 35Fig. 5 is a detail rear view, looking in the direction of the arrow 5 inFig. 2;

Fig. 6 is a detailfront view, looking in the direction of the arrow 6 inFig. 2;

d Fig. 7 is a detail sideelevation, looking in the direction of thearrow 7 in Fig. 1;

Fig. '8 is a sectional plan view, taken along the line 8-8 in Fig. 7

Fig. is an enlarged plan view of certain 45 parts;

Fig. 10 is a sectional side elevation, taken substantially along theline 1O 1O in Fig. 9;

Fig. 11 is a detail side elevation, looking .in the direction of thearrow 11 in Fig. 10,

50 and indicating mechanism.

314,032. Divided and this application filed April 2, No. 441,153.

Fig. 12 is a partial plan View, showing certain parts in a differentposition. i

Referring to the drawings, our improved measuring machine comprises astand or table 20 (Fig. 1) having guideways 21 and 22 26 is interposedbetween the under surface of the casing24 and the bottom of the guideway21, for a purpose to be described.

A plunger 27 is slidable in a bushing 28 fixed in the casing 24 and isprovided with a contact member 30 which may be secured thereinbyasetsorew 31 (Fig. 2). Access to the screw 31 may be had throughanopening 32in the bushing 28, said opening being normally closed by ascrew 33. A spring 34 presses the plunger 27 yieldingly outward and apin .35 limits the outward movement. The front end of the bushing 28 maybe provided with a cover plate 36through which the contact member 30 isslidable. The cover plate assists in preventing the access of dirt tothe A segment member 40 is pivoted at 41 in the casing 24 and forms anangle connection between the rear end of the plunger 27 and the lowerend of a spring-pressed plunger .42, slidable vertically in a bearingmember 43 mounted in a split holder 44 on the casing 24. The member 43may be secured in desired adjusted position by tightening the splitholder 44 by means of a clamping screw 45 (Fig. 5).

The plunger 42 is keyed in the bearing frame 43, as indicated at 46, andis provided with a vspring 47 yieldingly pressing the plunger downward.At its upper end, the plunger 42 engages the plunger 49 of a magnifyingand indicating device 50, preferably mounted on an upper projection 51(Fig. 2) of the bearing frame 43.

' The indicating device is provided with a pointer 52 movable by theplungers 42 and 49 over a dial 53. The dial 53 is preferably mounted ina ring 54 frictionally held on the casing of the indicator 50, so thatit may be turned angularly as desired in either direction.

The indicating device may be otherwise of any usual commercial form andthe remaining details thereof form no part of our pres ent invention.

A contact member or anvil is mounted in a square plun er 61 (Figs. 1 and2), which is slidably mounted in a stand 62. The stand 62 is adjustableforward and rearward in the front portion of the guideway 21 and may besecured in adjusted position in said guide way by a clamping screw 63.

A spring 64 (Fig. 4) is interposed between a shoulder 65on the plunger61 and a bushing 66 threaded in a cap 67 at the front end of the standor casing 62. The bushing 66 has a knurled head 68 for convenientadjustment of the tension on the spring 64. It will be understood thatthe spring 64 is very substantially stronger than the combined strengthof the springs 34 and 47 on the plunger 27 previously described.

A stop pin 70 (Fig. 1) in the stand 62 projects into a slot 71 in thesquare plunger 61 and engages an end wall of the slot, thereby limitingrearward movement of the anvil or contact member 60 and providing adefinite zero position thereof. A felt packing 7 3 prevents the entranceof dirt around. the plunger 6],.

A hand lever 75 is provided with a stud 76 3) pivoted in a fixed bearingin the stand 62 and having a member 77 secured thereto. The member 77has a .convex head 7 8 positioned in a slot 79 in the plunger 61. Byturning the handle 7 5 in the direction of the arrow a in Fig. 1 theplunger 61 may be forced forward or away from the work, compressing thespring 64. The head 78 has a limited lost motion in the slot 79.

The form of our invention shown herein is particularly adapted to themeasurement oftaps having only two lands or sets of teeth. Forpositioning such taps we provide a lever 120 (Fig. 9) pivoted on a stud121 fixed in a stand 122 adjustable in the transverse guideway 22 andsecured in adjusted position by a clamping screw 123 (Fig. 2).

A positioning member 124 is mounted in guideways 125 (Fig. 9) on thelever 120 and may be secured in position thereon by a clamping screw126. An opening 127 is formed in the member 124 in such a position thatits axis intersects the axis of the members 30 and 60 previouslydescribed. The opening 127 is very slightly larger than the outsidediameter of the tap to be measured and thus serves to center the tapbetween the members 30 and 60. A transverse opening 128 permits themembers 30 and 60 to engage a t7ap, as T extending through the opening12 In order to permit the tap T to be inserted through the opening 127we have provided a spring 130 (Fig. 11) engaging an offset arm 131 onthe lever 120 and acting to move the arm to the inoperative positionindicated in Fig. 12, such movement carrying the positioning member 124forward or away from the indicating plunger 30 to a point Where a tapmay be inserted through the opening 127 without engaging the point ofthe plunger 30.

A stud 133 extends through the stand 122, the spring 130 and the arm131, and is provided with a nut 134 by which the amount of swingingmovement may be limited.

For convenience in setting up the machine for different lots of taps, weprovide a graduation 136 (Fig. 9) on the positioning memher 124, inexact alignment with the center of the opening 127. We also provide agraduation 138 on a setting stand 139, mounted in the left hand portionof the guideway 22. In setting up the machine, the plunger 60 and itsstand may be adjusted until the tap T positioned by the member 124aligns the graduation 136 thereof with the graduation 138 on the settingstand 139.

Having described the details of construction of our invention asdesigned for measuring two-fluted taps, the method of operation thereofis as follows The handle 75 is first moved in the direction of the arrowat in Fig. 1 to withdraw the plunger 61, and a standard or master threadgauge is then placed in position between the two contact members 30 and60.

The casing 24 for the indicating plunger 30 is then adjusted forward orrearward to cause the plunger 30 to be engaged by the master gauge asthe latter is positioned by the member 60, and to cause said plunger 30to be moved inward in the bushing 22 a short distance, compressing thespring 34.

The bearing frame 43 is then adjusted axially to place the plunger 42under compression and to move the pointer 52 in the indicating device acertain angular amount, any one revolution, from its Z61O or baseposition.

The parts are secured in these adjusted positions and the dial ring 54is then turned on the indicating device 50 to bring the zero of the dialto correspond to the position of the arrow 52.

The rearward movement of the plunger 61 forces the contact member 60against one of the threaded lands of the taps T and forces the secondand opposite threaded land of the tap against the indicating contactmember 30. moving said member 30 rearward a certain. distance, dependingupon the exact diameter of the tap T Any variation in diameter will bemade evident by a glance at the indicating device 50, the pointerindicating the variation over size or under size by its movem nt in onedirection or the other from the fixed zero. The dial as shown is memberor anvil 60 is withdrawn by the handle (Fig. 1) as previously described,the spring 130 will swing the member 124 to the position shown in Fig.12, in which position the tap may be removed or inserted withoutstriking the points of the members 30 or 60.

By the use of the machine above described, we are able to inspect tapswith ease and rapidity and to very quickly and accurately determine anyvariation thereof, either over or under the standard diameter as fixedby the master gauge.

The points of the contact members 30 and 60 are suitably shaped toengage between the screw threads. The points are then generally hardenedor may be prnvided with diamond points. i

When a tap is held in a vertical position, as indicated in Fig. 7, itwill be clear that the anvil 60 and the indicating plunger 30 willengage the tap in different horizontal planes, determined by the pitchof the thread, the member 30 bein positioned above the anvil 60 by anamount equal to one-half of the lead of the tap. As this distance variesfor taps of different pitches, we provide a series of shims 26* ofdifferent thicknesses, so that a shim may be selected for a desiredpitch which will elevate the indicating plunger 30 by the desired amountabove the plane of the anvil 60.

Having described our improved measuring machine and its application totaps having two flutes, the use and utility of the machine will bereadily apparent. We do not wish to be limited to the details hereindisclosed, otherwise than as set forth in the claims, but what we doclaim is:

1. In a machine for measuring two-fluted taps, a contact member, anindicating device operable thereby, a positioning member opposed to saidcontact member, means to locate said positioning member in apredetermined normal position, means to withdraw said positioning memberfrom normal position, means to return said member to said predeterminednormal position, a device for locating a tap between said members, saiddevice being movable toward and from said contact member substantiallyalong the center line of said contact and positioning members, and meansto move said locating device away from said contact member when saidpositioning member is withdrawn from its predetermined normal position.

2. In a machine for measuring threaded work, a contact member, anindicating device operable thereby, a positioning member opposed to saidcontact member, means to locate said positioning member in apredetermined normal position, means to withdraw said positioning memberfrom normal position, means to return said member to said predeterminednormal position, a device for locating a tap between said members, saiddevice being movable toward and from said contact member, and a springto move said locating device away from said contact member when saidpositioning member is withdrawn from its predetermined normalposition.

3. In a machine for measuring threaded work, a contact member, anindicating device operable thereby, a positioning member opposed to saidcontact member, means to locate said positioning member in apredetermined normal position, means to withdraw said po-' sitioningmember from normal position, a spring to return said member to saidpredetermined normal position, a device for locating a tap between saidmembers, said device being movable toward and from said contact member,and a spring to move said locating device away from said contact memberwhen said positioning member is withdrawn from its predetermined normalposition, said first spring being substantially stronger than saidsecond spring and being efiective to overcome the pressure of saidsecond spring and also the resistance of the indicating device.

4. In a machine for measuring threaded work, a contact member, anindicating device operable thereby, a positioning member opposed to saidcontact member, means to locate said positioning member in apredetermined normal position, means to withdraw said positioning memberfrom normal position, means to return said member to said predeterminednormal position, a pivotally mounted lever extending between saidmembers and movable toward and from said contact member and having anaperture to receive and guide a tap, and a spring acting to urge saidlever away from said contact member.

5. The combination in a measuring machine as set forth in claim 4, inwhich the end portion of said lever in which said aperture is formed isremovable and replaceable, where-

